using System;

using Bentley.DgnPlatformNET;
using Bentley.DgnPlatformNET.Elements;

using static Bentley.DgnPlatformNET.DgnElementSetTool;

namespace Mstn.Toolkit.External
{

    public class UserPickTool : DgnElementSetTool
    {
        private Func<Element, bool> allowElement;
        private string prompt;
        private Action<ElementAgenda> operations;
        private UserPickTool(int toolId, int promptId) : base(toolId, promptId)
        {
        }
        public static void Setup(Func<Element, bool> allowElement, Action<ElementAgenda> operations, string prompt = "请选择元素")
        {
            UserPickTool tool = new(0, 0)
            {
                prompt = prompt,
                allowElement = allowElement,
                operations = operations,
            };

            tool.InstallTool();
        }

        /// <summary>
        /// 判断是否要启用框选或者划选
        /// </summary>
        /// <returns></returns>
        protected override UsesDragSelect AllowDragSelect()
        {
            return UsesDragSelect.Box;
        }

        ///// <summary>
        ///// 筛选拾取的元素
        ///// </summary>
        ///// <returns></returns>
        //protected override bool FilterAgendaEntries()
        //{
        //    for (uint i = 0; i < ElementAgenda.GetCount(); i++)
        //    {
        //        var elem = ElementAgenda.GetEntry(i);
        //        return allowElement(elem);
        //    }
        //    return false;
        //    //return base.FilterAgendaEntries();
        //}
        ///// <summary>
        ///// 通过点选、围栅还是选择集来填充ElementAgenda
        ///// </summary>
        ///// <returns></returns>
        //protected override ElementSource GetElementSource()
        //{
        //    return base.GetElementSource();
        //}
        /// <summary>
        /// 获取偏好选择方式
        /// </summary>
        /// <returns></returns>
        protected override ElementSource GetPreferredElementSource()
        {
            switch (AllowFence())
            {
                case UsesFence.Check:
                    if (UseActiveFence() && FenceManager.IsFenceActive)
                    {
                        return ElementSource.Fence;
                    }
                    break;
                case UsesFence.Required:
                    return ElementSource.Fence;
                case UsesFence.None:
                    break;
                default:
                    break;
            }
            switch (AllowSelection())
            {
                case UsesSelection.Check:
                    if (SelectionSetManager.IsActive())
                    {
                        return ElementSource.SelectionSet;
                    }
                    break;
                case UsesSelection.Required:
                    return ElementSource.SelectionSet;
                case UsesSelection.None:
                    break;
                default:
                    break;
            }
            return ElementSource.Pick;
        }
        /// <summary>
        /// 判断是否需要用户再点击左键才开始处理元素
        /// </summary>
        /// <returns></returns>
        protected override bool NeedAcceptPoint()
        {
            return false;
        }
        ///// <summary>
        ///// 
        ///// </summary>
        ///// <param name="ev"></param>
        ///// <param name="newSearch">是否重新搜索</param>
        ///// <remarks>newSearch=false:表明用户最后拾取的元素不是想要的，调用RemoveAgendaElement移除，并继续往后定位其他元素</remarks>
        //protected override void LocateOneElement(DgnButtonEvent ev, bool newSearch)
        //{
        //    base.LocateOneElement(ev, newSearch);
        //}
        ///// <summary>
        ///// 对ElementAgenda中的元素进行修改筛选
        ///// </summary>
        //protected override void ModifyAgendaEntries()
        //{
        //    base.ModifyAgendaEntries();
        //}
        ///// <summary>
        ///// 点击确认键（默认为左键）后触发，判断是否需要拾取元素
        ///// </summary>
        ///// <param name="ev"></param>
        ///// <returns></returns>
        //protected override bool OnDataButton(DgnButtonEvent ev)//
        //{
        //    //var promptId = "OnDataButton";

        //    NotificationManager.OutputPrompt(prompt);//将提示语输出到提示框中
        //    if (ElementSource.Pick == GetElementSource())
        //    {
        //        //光标变为点选状态
        //        BeginPickElements();
        //    }
        //    else if (ElementSource.SelectionSet == GetElementSource())
        //    {
        //        //是否需要用户输入额外的确认点才开始处理选择集元素/判断是否需要用户再点击左键才开始处理元素
        //        if (NeedPointForSelection())
        //        {

        //        }
        //        else
        //        {
        //            BuildAgenda(ev);
        //            ProcessAgenda(ev);
        //            OnModifyComplete(ev);
        //        }
        //        if (!NeedPointForDynamics())
        //        {
        //            if (ElementSource.Pick != GetElementSource())
        //            {
        //                BuildAgenda(ev);
        //            }
        //        }
        //    }

        //    return true;
        //}
        /// <summary>
        /// 修改完毕，对选择集中的元素进行处理
        /// </summary>
        /// <param name="ev"></param>
        /// <returns></returns>
        protected override bool OnModifyComplete(DgnButtonEvent ev)
        {
            operations(ElementAgenda);
            //for (uint i = 0; i < ElementAgenda.GetCount(); i++)
            //{
            //    var elem = ElementAgenda.GetEntry(i);
            //    operation(elem);
            //}
            NotificationManager.OutputPrompt("完成");//将提示语输出到提示框中
            return base.OnModifyComplete(ev);
        }
        /// <summary>
        /// 工具激活后执行
        /// </summary>
        protected override void OnPostInstall()
        {
            //var promptId = "OnPostInstall";
            //NotificationManager.OutputPrompt(promptId);//将提示语输出到提示框中
            NotificationManager.OutputPrompt(prompt);
            //var dgnModel = Session.Instance.GetActiveDgnModel();//获得当前的模型空间
            base.OnPostInstall();
        }
        /// <summary>
        /// 光标定位到某个元素时调用，判断是否支持该元素，能否被选中
        /// </summary>
        /// <param name="path"></param>
        /// <param name="cantAcceptReason">光标在上方时，进行提醒，为什么不能被选中</param>
        /// <returns></returns>
        protected override bool OnPostLocate(HitPath path, out string cantAcceptReason)
        {
            var elem = path.GetCursorElement();
            var b = allowElement(elem);
            cantAcceptReason = b ? path.GetCursorElement().Description : "元素不适用此功能";
            return b;
        }
        /// <summary>
        /// 点击重置键（默认为右键）触发
        /// </summary>
        /// <param name="ev"></param>
        /// <returns></returns>

        protected override bool OnResetButton(DgnButtonEvent ev)//
        {
            ExitTool();//退出工具
            return true;//返回
        }
        ///// <summary>
        ///// 重启工具时触发
        ///// </summary>
        protected override void OnRestartTool()
        {
            Setup(allowElement, operations, prompt);
        }
        ///// <summary>
        ///// 设置选择方式
        ///// </summary>
        ///// <param name="source"></param>
        //protected override void SetElementSource(ElementSource source)
        //{
        //    switch (source)
        //    {
        //        case ElementSource.Pick:
        //            break;
        //        case ElementSource.Fence:
        //            break;
        //        case ElementSource.SelectionSet:
        //            break;
        //        default:
        //            break;
        //    }
        //}
        /// <summary>
        /// 是否需要继续进行选择
        /// </summary>
        /// <param name="ev"></param>
        /// <returns></returns>
        protected override bool WantAdditionalLocate(DgnButtonEvent ev)
        {
            if (ev == null)//若没有选择到元素
            {
                return true;
            }
            if (ev.IsControlKey)//若检测到按动Ctrl行为
            {
                return true;
            }
            if (ElementAgenda.GetCount() == 0)//若选择集中没有元素
            {
                return true;
            }
            return false;
        }

        /*
         * 如果我们对通过参数传递进来的元素进行修改，并且返回SUCCESS的话，在_DoOperationForModify
         * 中会用修改后的元素替换掉原来的元素，当然前提是_IsModifyOriginal返回true。否则的话会直接
         * 把修改后的元素重新添加到Dgn文件中。
         */
        public override StatusInt OnElementModify(Element element)
        {
            return StatusInt.Error;
        }

    }
}